US5855323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for jetting, manufacturing and attaching uniform solder balls
Assignee: National Technology and Engineering Solutions of Sandia LLC
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Filing: 1996-11-13
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Granted: 1999-01-05
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Expires: 2016-11-13
Abstract
Abstract An apparatus and process for jetting molten solder in the form of balls directly onto all the metallized interconnects lands for a ball grid array package in one step with no solder paste required. Molten solder is jetted out of a grid of holes using a piston attached to a piezoelectric crystal. When voltage is applied to the crystal it expands forcing the piston to extrude a desired volume of solder through holes in the aperture plate. When the voltage is decreased the piston reverses motion creating an instability in the molten solder at the aperture plate surface and thereby forming spherical solder balls that fall onto a metallized substrate. The molten solder balls land on the substrate and form a metallurgical bond with the metallized lands. The size of the solder balls is determined by a combination of the size of the holes in the aperture plate, the duration of the piston pulse, and the displacement of the piston. The layout of the balls is dictated by the location of the hooks in the grid. Changes in ball size and layout can be easily accomplished by changing the grid plate. This invention also allows simple preparation of uniform balls for subsequent supply to BGA users.
Inventors
- 👤 Frederick G. Yost
- 👤 Darrel R. Frear
- 👤 David T. Schmale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:16
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; B; B05; B05B; B05B17/00; B05B17/04; B05B17/06; B05B17/0607; B05B17/0638; B23; B23K; B23K3/00; B23K3/06; B23K3/0607; B23K3/0623; H05K2203/00; H05K2203/01; H05K2203/0104; H05K2203/013; H05K2203/0134
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
120 words
An apparatus for simultaneously generating a plurality of solder balls, comprising: a) a reservoir comprising a means for heating to an operating temperature sufficient to melt solder and containing a working volume of melted solder; b) at least one aperture plate in fluid communication with the melted solder in said reservoir, comprising a plurality of apertures; and, c) means for generating a positive pressure pulse followed by a negative pressure pulse in the molten solder, wherein the positive pressure pulse causes separate volumes of molten solder to extrude through each of the apertures in the at least one aperture plate, and the negative pressure pulse causes a solder ball to detach from each of the separate volumes of molten solder.
Claim 2
Independent Claim
120 words
An apparatus for simultaneously generating a plurality of solder balls, comprising: a) a reservoir comprising a means for heating to an operating temperature sufficient to melt solder and containing a working volume of melted solder; b) at least one aperture plate in fluid communication with the melted solder in said reservoir, comprising a plurality of apertures; and, c) means for generating a positive pressure pulse followed by a negative pressure pulse in the molten solder, wherein the positive pressure pulse causes separate volumes of molten solder to extrude through each of the apertures in the at least one aperture plate, and the negative pressure pulse causes a solder ball to detach from each of the separate volumes of molten solder.
Claim 3
Dependent Claim
48 words
The invention of claim 1 wherein said reservoir comprises a chamber shaped so that when said means for generating a positive pressure pulse followed by a negative pressure pulse is activated the molten solder has a flow stream substantially parallel to an axis of said plurality of apertures.
Claim 4
Dependent Claim
17 words
The invention of claim 1 wherein said aperture plate comprises a material not wetted by melted solder.
Claim 5
Dependent Claim
24 words
The invention of claim 1 wherein said means for generating a positive pressure pulse followed by a negative pressure pulse comprises a piston-driven apparatus.
Claim 6
Dependent Claim
15 words
The invention of claim 4 wherein said piston-driven apparatus comprises at least one piezoelectric crystal.
Claim 7
Dependent Claim
21 words
The invention of claim 4 wherein said piston driven apparatus further comprises a controller for controlling piston speed and piston travel.
Claim 8
Dependent Claim
15 words
The invention of claim 4 wherein said piston driven apparatus comprises a shaped piston face.
Claim 9
Dependent Claim
44 words
The invention of claim 1 wherein said means for generating a positive pressure pulse followed by a negative pressure pulse comprises a member from the group consisting of a cam driven apparatus, a fluid drive apparatus, a gas driven apparatus, and an electromagnetic field.
Claim 10
Dependent Claim
17 words
The invention of claim 1 further comprising a means for controlling the atmosphere surrounding the melted solder.
Claim 11
Independent Claim
86 words
A method for simultaneously generating a plurality of solder balls, the method comprising the steps of: a) melting solder in a heated reservoir comprising at least one aperture plate, said at least one aperture plate comprising a plurality of apertures patterned consistent with the predetermined locations on a surface; b) extruding a volume of solder through each aperture by applying a positive pressure pulse to the melted solder; and c) detaching a plurality of solder balls by applying a negative pressure pulse to the melted solder.
Claim 12
Independent Claim
86 words
A method for simultaneously generating a plurality of solder balls, the method comprising the steps of: a) melting solder in a heated reservoir comprising at least one aperture plate, said at least one aperture plate comprising a plurality of apertures patterned consistent with the predetermined locations on a surface; b) extruding a volume of solder through each aperture by applying a positive pressure pulse to the melted solder; and c) detaching a plurality of solder balls by applying a negative pressure pulse to the melted solder.
Claim 13
Dependent Claim
42 words
The method of claim 10 wherein the steps of extruding a volume of solder and of detaching a plurality of solder balls comprise the melted solder in the heated reservoir having a flow stream substantially parallel to an axis of the apertures.
Claim 14
Dependent Claim
26 words
The method of claim 10 wherein the steps of extruding a volume of solder and of detaching a plurality of solder balls comprise driving a piston.
Claim 15
Dependent Claim
19 words
The method of claim 12 wherein the step of driving a piston comprises activating at lest one piezoelectric crystal.
Claim 16
Dependent Claim
19 words
The method of claim 12 wherein the step of driving a piston comprises controlling piston speed and piston travel.
Claim 17
Dependent Claim
18 words
The method of claim 12 wherein the step of driving a piston comprises driving a shaped piston face.
Claim 18
Dependent Claim
38 words
The method of claim 10 wherein the step of extruding a volume of solder comprises providing a member from the group consisting of a cam driven apparatus, a fluid driven apparatus, a gas driven-apparatus, and an electromagnetic field.
Claim 19
Dependent Claim
17 words
The method of claim 10 further comprising the step of controlling the atmosphere surrounding the melted solder.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-01-04 | 2002-07-06 | 2003-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-01-04 | 2006-07-06 | 2007-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-01-04 | 2010-07-06 | 2011-01-05 | $7700.00 | Window Closed / Lapsed |